Internal-combustion engine



D. A. DAVISON INTERNAL COMBUSTION ENGINE Sept. 18, 1928. 1,684,435

Original Filed April 22, 1927 2 Sheets-Sheet 1 Sept. 18, 1928.

D. A. DAVISON INTERNAL COMBUSTION ENGINE W Z ll/ w z/ w E, 2 if. M E m 2 w 4 A w a 1 A W 1 m 5 m 4 V 0 W 00 a0 Patented Sept. 18, 1928.

UNITED STATES DORSETT A. DAVISON, OF RICHMOND, VIRGINIA.

INTERNAL-COMBUSTION ENGINE.

Original application filed April 22, 1927, Serial No. 185,898. Divided and this application filed April 22,

In an application filed by me of even date herewith, serially numbered 185,898, I disclosed two specific forms of a rotary valve mechanism for controlling the intake of explosive gases to and the exhaust of burnt gases from internal combustion engines, each of said forms of my invention including a valve in the form of a split ring and a rotary liner for driving same, a toothed connection being provided between the valve and liner according to one of the forms of my lnvention and the valve and liner being formed integrall with one another according to the other orm thereof. This application is directed specifically to the latter form of my invention and therefore constitutes a division of my above identified application.

A valve mechanism of the type mentioned in which a valve in the form of a split ring has a toothed connection with a driver therefor in the form of a rotary liner is beneficial for various reason-s, some of which are set forth in my prior Patent 1,271,137 and other of which are set forth in the application of which this application is a division. However, despite the numerous advantages inherent to a toothed connection between a rotary valve and a liner for driving the same, such a connection is diflicult and expensive to produce and moreover it permits relative lateral shifting movement between the valve and liner, which in turn may permit the valve to distort, bind and leak under the influence of the varying pressures to which it is subjected in operation. In addition, a toothed connection, since it may permit relative lateral movement between the valve and liner, manifestly does not assure a desired concentric relation of the valve and liner with respect to the cylinder.

It is my present purpose, therefore, to provide a valve in the form of a split ring and a driver therefor in the form of a liner so connected therewith as to retain most of the advantages inherent to a toothed connection between such parts as shown in my application serially numbered 185,898, and at the same time to eliminate the disadvan tages mentioned in respect to a toothed connection, my present structure being relatively cheap and easy to produce, capable of maintaining a concentric relation of the valve and liner with respect to the cylinder and of supporting the valve at the point where it is subjected during its operation Serial No. 185,899.

to pressures having a tendency to distort same.

With the foregoing and other purposes in view, my invention consists in the novel features of construction, combination and arrangement of parts as will be hereinafter more fully described, illustrated in the accompanying drawings and defined in the appended claims.

In the drawings, wherein like characters of reference denote corresponding parts in the different views Fig. 1 is a vertical transverse section through an engine equipped with my improved valve mechanism;

Fig. 2, a horizontal section on a slightly enlarged scale taken approximately on the line 22 of Fig. 1;

Fig. 3, a vertical transverse section through a portion of the engine cylinder with the valve and liner removed therefrom to show the arrangement of oil grooves therein; and

Fig. 4, a perspective view of my improved valve and a portion of the liner for driving same. Referring to the drawings in detail, A designates, generally, an internal combustion engine of conventional design including, as usual, a cylinder 10, a crank case 12, a crank shaft 14, a piston 16 and a rod 18 connecting sald piston with said crank shaft.

In accordance with my invention a liner 20 is mounted within cylinder 10 and piston 16 operates within said liner.

Liner 20 is provided around its outer face with gear teeth 22 with which a gear 24 meshes, said gear being driven in any suitable manner, as, for example, from the crank shaft 14, whereby said liner is rotated during reciprocation of piston 16 therein.

Liner 20 is designed to drive a rotatable valve 26 for controlling the inlet of explosive gases to and the exhaust of burnt gases from the engine, said valve being in the form of a split ring having a port 28 formed therein partly in one end and partly in the other end thereof formed by the split adapted, during rotation of the valve, to register successively with an intake port 30 and an exhaust port 32 formed in and so spaced circumferentially of the cylinder that explosive gases will be supplied to and burnt gases exhausted from the cylinder at the roper times according to the movement of t e piston 16 within the liner to cause the engine to operill) ate preferably on the four cycle principle, to which end the gear ratio between the crank shaft 14 and liner 20 preferably is such that the liner and consequently the valve 26 will rotate at one-half the speed of the crank shaft.

A ball bearing 34 between a shoulder on liner 20 and a shoulder on cylinder 10 serves to hold said liner against outward longitudinal movement with respect to said cylinder, while another ball bearing 36 between the inner end of the liner and a member 38 secured in any suitable manner to a portion of the cylinder serves to hold said liner against inward longitudinal movement, said ball bearings, however, permitting free rotation of said liner as is manifest.

Preferably the outside diameter of liner 20 is slightly less than the inside diameter of the cylinder 10 to permit expansion of the liner and to provide a lubricant receiving space between the cylinder and liner, an expansible ring or rings 40 being provided near the inner end of the liner to form a seal to prevent lubricant inthe space between said liner and cylinder from flowing into the crank case, which seal in turn prevents any-leakage of gas from the interior of the liner and valve around the outside of these parts into the crank case as is apparent.

The outer face of valve 26 seats against the inner face of cylinder 10 and by reason of the fact that said valve is split and rotatable it follows that one of the ends thereof formed by the split will constitute 'what may be termed the lead end and the other the trailing end of said valve as regards its direction of rotation. A peculiarity of a split ring seating against the inner face of a cylinder is that if any driving force for rotating the ring is applied to the trailing end portion thereof the ring will tend to bind against the cylinder wall, whereas if the driving force is applied only to the lead end portion of such a ring it will rotate freely within the cylinder without tendency to bind thereagainst.

My present valve and liner are formed integrally with one another and are joined together only throughout the lead end portion of the valve as regards its direction of rotation, the result being that the valve rotates freely within the cylinder under the influence of the driving force imparted thereto by the liner and that by reason of the rigid connection between the valve and liner each tends to hold the other at all times against any relative lateral movement bodily one with respect to the other, so that the concentricity of both with respect to the cylinder is maintained. Furthermore. the arrangement of the ports 30, 32 necessarily being such, if the engine is designed to operate on the four cycle principle, that the exhaust port becomes fully blanked by the valve 26 when piston 16 is substantially at its limit of outward movement on its exhaust stroke, it follows that the valve must rotate in a direction which will result in its lead end portion overlying and blanking the exhaust port during the succeeding intake or suction stroke of the piston, and since a partial vacuum is created within the valve during the intake stroke of the piston the greater external or atmospheric pressure against the outside of the valve throughout the area thereof exposed by the exhaust port will have a tendency to force the lead end portion of the valve laterally inwardly, but since the rigid connection between the valve and liner is located at the lead end portion of the valve such rigid coni nection obviously will be effective to hold said lead end portion of the valve against inward lateral movement despite a greater pressure against the outer face thereof than against the inner face thereof.

To assist the rigid connecting portion between the valve and liner in holding the lead end portion of the valve against inward lateral movement the trailing end portion may be provided with an inwardly disposed extension or.extensions 44 overlapping an outwardly disposed extension or extensions 46 on the lead end portion. The inclusion of this arrangement is optional, however, and may be dispensed with if desired.

In producing a one piece valve and liner a tube first is machined to reduce slightly the external diameter of the portion thereof that is to constitute the liner with respect to the portion thereof that is to constitute the valve, this for the purpose of affording the lubricant space aforementioned between the cylinder and liner when the latter is arranged within the former. By means of a saw or other tool a kerf 48 is formed at the junction of the liner with the valve to separate them except for a minor circumferential portion 50 which is left to rigidly connect them. The valve then is split at a point in line with one end of the kerf 48, the proper end being determined according to the direction in which the valve is intended to rotate, and eitherbefore or after said valve is split. port 28 is formed therein. As shown in this instance port 28 is of less depth than the length of the valve, but obviously it might extend from end to end of the valve in which event the port itself would constitute the necessary split in the valve.

Preferably the liner 20 and valve 26 are so proportioned and so positioned within the cylinder 10 that the kerf 48 is located in the plane or substantially in the plane of the outer end of the piston 16 when the latter is at its limit of outward movement within the liner, so that oil which escapes from the crank case past the piston, and which is scraped from the inner wall of the liner by the outer end of the piston during the normal operation of the engine, will be carried by the outer end of the piston to a point in valve and liner, thereby to maintain the space between the c linder and liner constantly filled with oil and to maintain the outer faces of the valve and liner constantly and effectively lubricated. In addition, by locating the kerf as mentioned the pressure within the valve and liner present during compression and power strokes of the piston is allowed, throughout said strokes, to exert itself upon the trapped oil contained in the space between the cylinder and liner and between the cylinder and valve, with the result that said pressure will be distributed evenly by the oil entirely around the outside of the liner and valve and the internal and external pressures on the liner and valve will be balanced, resulting in a free turning liner and valve.

It is contem lated that all of the oil necessary for the hi rieation of the liner and valve will be supplied to these parts from the crank case in the manner just stated, but. if desired, a passage 42 may be provided through the cylinder wall in communication with the space between the cylinder and liner whereby lubricant may be supplied by a pump or any other suitable means to said space.

An annular groove 50 is formed in the cylinder wall in alinement with kerf 48 to receive oil that is thrown outwardly through the latter, and longitudinally extending grooves 52 also are formed in said cylinder in communication with said annular groove and extending therefrom towards the outer edge of the valve whereby the flow of oil under the influence of centrifugal force and the pressures aforementioned to the outer face of the valve as well as the balancing of pressures inside and outside the valve will be greatly enhanced, it being apparent that asportions of the valve pass the grooves 52 they be effectively lubricated by the lubricant contained therein. Obviously, instead of the grooves 50 being formed in the cylinder wall they may as readily be formed in the outer or seating surface of the valve.

While in the foregoing I have described my invention as applied to asingle cylinder engine, it is manifest that it is only necessary to duplicate the structure for each cylinder of a multiple cylinder engine.

From the foregoing description considered in connection with the accompanying drawings it is believed that the construction, operation and advantages of my present improvements will be fully understood. I desire to point out, however, that various changes and desirable additions may be made in and to the structure shown within the spirit and scope of my invention as defined in the ap pended claims.

I claim:

1. A valve mechanism including a split rotatable hollow cylindrical valve member, a rotatable hollow cylindrical liner for rotating said valve member, and a rigid connection between said valve member and liner of less circumferential extent than the distance around said valve member located at the lead end portion of said valve member as regards its direction of rotation.

2. A valve mechanism including a rotatable valve member having lead and trailing ends, and a rotatable liner for rotating same, said valve member and liner being formed integrally with one another and a kerf being formed at the junction of said valve member with said liner throughout the circumferential extent of the valve member with the exception of a minor circumferential portion thereof located at its lead end as regards its direction of rotation.

3. A valve mechanism including a split rotatable hollow cylindrical valve member and a rotatable hollow cylindrical liner for rotating same, a kerf of less circumferential extent than the distance around said valve member being formed at the junction of said valve member with said liner and one end of said kerf being located substantially at the point where said valve member is split.

4. In an engine, a cylinder havin an intake and an exhaust port, a rotatab e valve hav ng a port therein adapted to register during ts rotation first with said intake port to admit operating fluid to said cylinder and then with said exhaust port to permit exhaust products to escape from said cylinder, a rotatable liner for rotatin said valve, said liner and valve being rigidly connected together throughout a portion of their circumferential extent and being loose with respect to one another throughout the remainder of their circumferential extent, the rigid connection between said valve and liner being so located .with respect to the port in said valve that when said port registers with the intake port in the cylinder said rigid connection is disposed in alinement with the exhaust port in the c linder, whereby the valve is held against inward collapse due to the exhaust pressure against the outer face thereof.

In testimony whereof I hereunto aflix my signature.

DORSETT A. DAVISON. 

